Author
Topic: Steam Autopilots (Read 16981 times)

We made an extensive list of autopilots to assist in common mission maneuvers. Some autopilots are specific to the Apollo missions, some are generic.

When a green dot shows next to the AUTOPILOT tab, an autopilot is currently running. Some autopilots run in a safe mode. You need to press the padlock icon to unlock.Some autopilots start in paused mode. You need to first select the required parameters and then press the start button to begin running the autopilot.

LAUNCH TO ORBIT (Program 11) Launches the Saturn V stack to Earth parking orbit. 'Altitutde' is the orbital altitude in kilometers and 'Bearing' is in degrees from true north. The spacecraft must be launched from a port, ie, the Kennedy Space Center launchpad.

TLI LUNARINJ (Program 15) Fires the S-IVB engine into translunar injection orbit. This requires the spacecraft to be within 1 degree of the orbital plane with respect to the Moon. It will propel the Apollo stack to an orbit with an apogee nearing the distance at which the lunar sphere of influence will trap the spacecraft. Upon nearing the Moon, further mid-course corrections may be needed to finetune the lunar orbit insertion. In reality, this TLI was performed by the Instrument Unit on the S-IVB stage and the AGC program 15 (this one) was a backup.

LOI LUNARORBIT (Program 16) Computes and performs the engine burn required to get trapped in lunar orbit. It assumes the spacecraft is following a hyperbolic orbit (an open orbit where eccentricity is greater than 1).

LUNAR DOI (Program 17) Descent Orbit Initialization procedure.

PROGRADE (Program 20) Progrades the spacecraft, orienting the engine with the direction of travel. This is useful for increasing orbital velocity.

RETROGRADE (Program 21) Retrogrades the spacecraft, orienting the engine against the direction of travel. This is useful for reducing orbital velocity.

NORMAL PLUS (Program 22) Sets the spacecraft pointing to the perpendicular of the orbital plane. Useful for changing orbital inclination.

REENTRY (Program 92) Deorbits the Space Shuttle until a vector state fit for reentry to Kennedy Space Center.

CIRCULARIZE TOP (Program 101) Circularizes the orbit to the altitude of the highest point.

CIRCULARIZE LOWER (Program 102) Circularizes the orbit to the altitude of the lowest point.

ALIGN PLANE (Program 103) Aligns the orbital plane (select target in ORBIT visualizer). The first step to a successful Hohmann Transfer Orbit is to have both orbits share the same orbital plane. To do so you need to perform a normal +/- burn at the points where the two orbit planes intersect. These are commonly referred to as the Ascending Node (AN) and Descending Node (DN).